<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>加载动画</title>
    <style>
        .loading-box{
            margin: 70px;
        }
        .loader {
            width: 250px;
            height: 50px;
            line-height: 50px;
            text-align: center;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            font-family: helvetica, arial, sans-serif;
            text-transform: uppercase;
            font-weight: 900;
            color: #99ddcc;
            letter-spacing: 0.2em;
        }
        .loader::before, .loader::after {
            content: "";
            display: block;
            width: 15px;
            height: 15px;
            background: #99ddcc;
            position: absolute;
            animation: load .7s infinite alternate ease-in-out;
        }

        .loader::before {
            top: 0;
        }

        .loader::after {
            bottom: 0;
        }
        @keyframes load {
            0% { left: 0; height: 30px; width: 15px }
            50% { height: 8px; width: 40px }
            100% { left: 235px; height: 30px; width: 15px}
        }
    </style>
</head>
<body>
<div align="center" class="loading-box">
    <div class="loader">Loading...</div>
</div>
<script src="../vendors/jQuery/jquery-3.3.1.min.js"></script>
<script type="text/javascript">

</script>
</body>
</html>